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be2919d835
Add new charge-current-limit feature to gpio-charger. Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
401 lines
10 KiB
C
401 lines
10 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
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* Driver for chargers which report their online status through a GPIO pin
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*/
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#include <linux/device.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/power_supply.h>
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#include <linux/slab.h>
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#include <linux/of.h>
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#include <linux/gpio/consumer.h>
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#include <linux/power/gpio-charger.h>
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struct gpio_mapping {
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u32 limit_ua;
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u32 gpiodata;
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} __packed;
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struct gpio_charger {
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struct device *dev;
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unsigned int irq;
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unsigned int charge_status_irq;
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bool wakeup_enabled;
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struct power_supply *charger;
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struct power_supply_desc charger_desc;
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struct gpio_desc *gpiod;
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struct gpio_desc *charge_status;
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struct gpio_descs *current_limit_gpios;
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struct gpio_mapping *current_limit_map;
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u32 current_limit_map_size;
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u32 charge_current_limit;
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};
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static irqreturn_t gpio_charger_irq(int irq, void *devid)
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{
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struct power_supply *charger = devid;
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power_supply_changed(charger);
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return IRQ_HANDLED;
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}
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static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy)
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{
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return power_supply_get_drvdata(psy);
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}
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static int set_charge_current_limit(struct gpio_charger *gpio_charger, int val)
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{
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struct gpio_mapping mapping;
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int ndescs = gpio_charger->current_limit_gpios->ndescs;
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struct gpio_desc **gpios = gpio_charger->current_limit_gpios->desc;
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int i;
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if (!gpio_charger->current_limit_map_size)
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return -EINVAL;
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for (i = 0; i < gpio_charger->current_limit_map_size; i++) {
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if (gpio_charger->current_limit_map[i].limit_ua <= val)
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break;
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}
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mapping = gpio_charger->current_limit_map[i];
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for (i = 0; i < ndescs; i++) {
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bool val = (mapping.gpiodata >> i) & 1;
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gpiod_set_value_cansleep(gpios[ndescs-i-1], val);
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}
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gpio_charger->charge_current_limit = mapping.limit_ua;
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dev_dbg(gpio_charger->dev, "set charge current limit to %d (requested: %d)\n",
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gpio_charger->charge_current_limit, val);
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return 0;
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}
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static int gpio_charger_get_property(struct power_supply *psy,
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enum power_supply_property psp, union power_supply_propval *val)
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{
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struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);
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switch (psp) {
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case POWER_SUPPLY_PROP_ONLINE:
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val->intval = gpiod_get_value_cansleep(gpio_charger->gpiod);
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break;
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case POWER_SUPPLY_PROP_STATUS:
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if (gpiod_get_value_cansleep(gpio_charger->charge_status))
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val->intval = POWER_SUPPLY_STATUS_CHARGING;
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else
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val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
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break;
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case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
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val->intval = gpio_charger->charge_current_limit;
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break;
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default:
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return -EINVAL;
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}
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return 0;
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}
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static int gpio_charger_set_property(struct power_supply *psy,
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enum power_supply_property psp, const union power_supply_propval *val)
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{
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struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);
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switch (psp) {
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case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
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return set_charge_current_limit(gpio_charger, val->intval);
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default:
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return -EINVAL;
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}
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return 0;
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}
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static int gpio_charger_property_is_writeable(struct power_supply *psy,
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enum power_supply_property psp)
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{
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switch (psp) {
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case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
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return 1;
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default:
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break;
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}
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return 0;
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}
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static enum power_supply_type gpio_charger_get_type(struct device *dev)
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{
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const char *chargetype;
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if (!device_property_read_string(dev, "charger-type", &chargetype)) {
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if (!strcmp("unknown", chargetype))
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return POWER_SUPPLY_TYPE_UNKNOWN;
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if (!strcmp("battery", chargetype))
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return POWER_SUPPLY_TYPE_BATTERY;
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if (!strcmp("ups", chargetype))
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return POWER_SUPPLY_TYPE_UPS;
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if (!strcmp("mains", chargetype))
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return POWER_SUPPLY_TYPE_MAINS;
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if (!strcmp("usb-sdp", chargetype))
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return POWER_SUPPLY_TYPE_USB;
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if (!strcmp("usb-dcp", chargetype))
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return POWER_SUPPLY_TYPE_USB;
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if (!strcmp("usb-cdp", chargetype))
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return POWER_SUPPLY_TYPE_USB;
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if (!strcmp("usb-aca", chargetype))
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return POWER_SUPPLY_TYPE_USB;
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}
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dev_warn(dev, "unknown charger type %s\n", chargetype);
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return POWER_SUPPLY_TYPE_UNKNOWN;
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}
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static int gpio_charger_get_irq(struct device *dev, void *dev_id,
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struct gpio_desc *gpio)
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{
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int ret, irq = gpiod_to_irq(gpio);
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if (irq > 0) {
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ret = devm_request_any_context_irq(dev, irq, gpio_charger_irq,
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IRQF_TRIGGER_RISING |
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IRQF_TRIGGER_FALLING,
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dev_name(dev),
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dev_id);
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if (ret < 0) {
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dev_warn(dev, "Failed to request irq: %d\n", ret);
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irq = 0;
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}
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}
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return irq;
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}
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static int init_charge_current_limit(struct device *dev,
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struct gpio_charger *gpio_charger)
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{
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int i, len;
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u32 cur_limit = U32_MAX;
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gpio_charger->current_limit_gpios = devm_gpiod_get_array_optional(dev,
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"charge-current-limit", GPIOD_OUT_LOW);
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if (IS_ERR(gpio_charger->current_limit_gpios)) {
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dev_err(dev, "error getting current-limit GPIOs\n");
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return PTR_ERR(gpio_charger->current_limit_gpios);
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}
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if (!gpio_charger->current_limit_gpios)
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return 0;
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len = device_property_read_u32_array(dev, "charge-current-limit-mapping",
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NULL, 0);
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if (len < 0)
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return len;
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if (len == 0 || len % 2) {
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dev_err(dev, "invalid charge-current-limit-mapping length\n");
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return -EINVAL;
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}
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gpio_charger->current_limit_map = devm_kmalloc_array(dev,
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len / 2, sizeof(*gpio_charger->current_limit_map), GFP_KERNEL);
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if (!gpio_charger->current_limit_map)
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return -ENOMEM;
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gpio_charger->current_limit_map_size = len / 2;
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len = device_property_read_u32_array(dev, "charge-current-limit-mapping",
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(u32*) gpio_charger->current_limit_map, len);
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if (len < 0)
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return len;
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for (i=0; i < gpio_charger->current_limit_map_size; i++) {
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if (gpio_charger->current_limit_map[i].limit_ua > cur_limit) {
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dev_err(dev, "charge-current-limit-mapping not sorted by current in descending order\n");
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return -EINVAL;
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}
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cur_limit = gpio_charger->current_limit_map[i].limit_ua;
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}
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/* default to smallest current limitation for safety reasons */
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len = gpio_charger->current_limit_map_size - 1;
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set_charge_current_limit(gpio_charger,
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gpio_charger->current_limit_map[len].limit_ua);
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return 0;
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}
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/*
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* The entries will be overwritten by driver's probe routine depending
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* on the available features. This list ensures, that the array is big
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* enough for all optional features.
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*/
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static enum power_supply_property gpio_charger_properties[] = {
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POWER_SUPPLY_PROP_ONLINE,
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POWER_SUPPLY_PROP_STATUS,
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POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX,
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};
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static int gpio_charger_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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const struct gpio_charger_platform_data *pdata = dev->platform_data;
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struct power_supply_config psy_cfg = {};
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struct gpio_charger *gpio_charger;
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struct power_supply_desc *charger_desc;
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struct gpio_desc *charge_status;
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int charge_status_irq;
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int ret;
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int num_props = 0;
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if (!pdata && !dev->of_node) {
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dev_err(dev, "No platform data\n");
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return -ENOENT;
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}
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gpio_charger = devm_kzalloc(dev, sizeof(*gpio_charger), GFP_KERNEL);
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if (!gpio_charger)
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return -ENOMEM;
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gpio_charger->dev = dev;
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/*
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* This will fetch a GPIO descriptor from device tree, ACPI or
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* boardfile descriptor tables. It's good to try this first.
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*/
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gpio_charger->gpiod = devm_gpiod_get_optional(dev, NULL, GPIOD_IN);
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if (IS_ERR(gpio_charger->gpiod)) {
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/* Just try again if this happens */
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return dev_err_probe(dev, PTR_ERR(gpio_charger->gpiod),
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"error getting GPIO descriptor\n");
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}
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if (gpio_charger->gpiod) {
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gpio_charger_properties[num_props] = POWER_SUPPLY_PROP_ONLINE;
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num_props++;
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}
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charge_status = devm_gpiod_get_optional(dev, "charge-status", GPIOD_IN);
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if (IS_ERR(charge_status))
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return PTR_ERR(charge_status);
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if (charge_status) {
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gpio_charger->charge_status = charge_status;
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gpio_charger_properties[num_props] = POWER_SUPPLY_PROP_STATUS;
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num_props++;
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}
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ret = init_charge_current_limit(dev, gpio_charger);
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if (ret < 0)
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return ret;
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if (gpio_charger->current_limit_map) {
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gpio_charger_properties[num_props] =
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POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX;
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num_props++;
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}
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charger_desc = &gpio_charger->charger_desc;
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charger_desc->properties = gpio_charger_properties;
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charger_desc->num_properties = num_props;
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charger_desc->get_property = gpio_charger_get_property;
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charger_desc->set_property = gpio_charger_set_property;
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charger_desc->property_is_writeable =
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gpio_charger_property_is_writeable;
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psy_cfg.of_node = dev->of_node;
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psy_cfg.drv_data = gpio_charger;
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if (pdata) {
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charger_desc->name = pdata->name;
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charger_desc->type = pdata->type;
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psy_cfg.supplied_to = pdata->supplied_to;
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psy_cfg.num_supplicants = pdata->num_supplicants;
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} else {
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charger_desc->name = dev->of_node->name;
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charger_desc->type = gpio_charger_get_type(dev);
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}
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if (!charger_desc->name)
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charger_desc->name = pdev->name;
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gpio_charger->charger = devm_power_supply_register(dev, charger_desc,
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&psy_cfg);
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if (IS_ERR(gpio_charger->charger)) {
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ret = PTR_ERR(gpio_charger->charger);
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dev_err(dev, "Failed to register power supply: %d\n", ret);
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return ret;
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}
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gpio_charger->irq = gpio_charger_get_irq(dev, gpio_charger->charger,
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gpio_charger->gpiod);
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charge_status_irq = gpio_charger_get_irq(dev, gpio_charger->charger,
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gpio_charger->charge_status);
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gpio_charger->charge_status_irq = charge_status_irq;
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platform_set_drvdata(pdev, gpio_charger);
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device_init_wakeup(dev, 1);
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return 0;
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}
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#ifdef CONFIG_PM_SLEEP
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static int gpio_charger_suspend(struct device *dev)
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{
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struct gpio_charger *gpio_charger = dev_get_drvdata(dev);
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if (device_may_wakeup(dev))
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gpio_charger->wakeup_enabled =
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!enable_irq_wake(gpio_charger->irq);
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return 0;
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}
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static int gpio_charger_resume(struct device *dev)
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{
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struct gpio_charger *gpio_charger = dev_get_drvdata(dev);
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if (device_may_wakeup(dev) && gpio_charger->wakeup_enabled)
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disable_irq_wake(gpio_charger->irq);
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power_supply_changed(gpio_charger->charger);
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return 0;
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}
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#endif
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static SIMPLE_DEV_PM_OPS(gpio_charger_pm_ops,
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gpio_charger_suspend, gpio_charger_resume);
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static const struct of_device_id gpio_charger_match[] = {
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{ .compatible = "gpio-charger" },
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{ }
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};
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MODULE_DEVICE_TABLE(of, gpio_charger_match);
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static struct platform_driver gpio_charger_driver = {
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.probe = gpio_charger_probe,
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.driver = {
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.name = "gpio-charger",
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.pm = &gpio_charger_pm_ops,
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.of_match_table = gpio_charger_match,
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},
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};
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module_platform_driver(gpio_charger_driver);
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MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
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MODULE_DESCRIPTION("Driver for chargers only communicating via GPIO(s)");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:gpio-charger");
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